Walter Shaub Jr., the Obama-appointed director of the Office of Government Ethics (OGE), announced Thursday he will be stepping down from his post six months early.

Shaub, described by the Washington Post as “the federal government’s most persistent critic of the Trump administration’s approach to ethics,” will leave office effective July 19 and become the senior ethics director of the non-profit Campaign Legal Center (CLC). He posted his resignation letter, which gave no specific reason for his departure, to his personal Twitter:

Later, Shaub told National Public Radio that “The current situation has made it clear that the ethics program needs to be stronger than it is. At the Campaign Legal Center, I’ll have more freedom to push for reform. I’ll also be broadening my focus to include ethics issues at all levels of government.”

The CLC is an ostensibly non-partisan group that has taken hundreds of thousands of dollars from left-wing billionaire George Soros. In 2010 and 2011, the group was instrumental in urging the IRS to open its now-infamous targeted investigations into conservative and “Tea Party” non-profits with a series of letters drafted along with other Soros-funded groups.